Refrigerant shutoff device and air conditioning system

Abstract

To provide a refrigerant shutoff device and an air conditioning system that appropriately shut off the refrigerant regardless of the location of the refrigerant leak. [Solution] A refrigerant shutoff device 50 includes a refrigerant flow path that branches into a first refrigerant flow path 51 and a second refrigerant flow path 52 and merges, wherein the first refrigerant flow path 51 includes a check valve 512 that allows refrigerant to pass in a first direction and a shutoff valve 511 that shuts off the flow of refrigerant, and the second refrigerant flow path 52 includes a refrigerant flow direction limiting mechanism 521 that restricts the direction in which the refrigerant flows to a second direction different from the first direction, and in the first refrigerant flow path 51, the shutoff valve 511 is positioned upstream of the check valve 512 in the first direction.

Description

Technical Field

[0001] The present invention relates to a refrigerant cutoff device and an air conditioner that prevent refrigerant leakage.

Background Art

[0002] In recent years, from the perspective of reducing the environmental load, air conditioners are required to use refrigerants with a low global warming potential (GWP). Some low-GWP refrigerants are slightly flammable or flammable, and air conditioners may require safety measures defined by standards. As an example of safety measures, for example, when a refrigerant is detected, ventilation or agitation is performed so that the concentration of the leaked refrigerant does not reach the lower flammability limit, or a method of blocking the flow of the refrigerant in the refrigerant piping is used.

[0003] In the method of blocking the flow of the refrigerant, it is required to block the flow of the refrigerant from the outdoor unit to the indoor unit, prevent liquid seal in the refrigerant piping on the indoor unit side from the refrigerant cutoff device when the flow of the refrigerant is blocked, and respond to the bidirectional flow of the refrigerant due to cooling / heating operation. For this reason, a refrigerant cutoff device using a shutoff valve, a pressure regulating valve, etc. is known.

[0004] Regarding this point, for example, in Japanese Patent No. 7415017 (Patent Document 1), an expansion valve, a liquid-side shutoff valve, and a gas-side shutoff valve are provided in an expansion valve unit, and a configuration in which the liquid-side shutoff valve is provided between the expansion valve and the indoor heat exchanger is disclosed. According to Patent Document 1, since the refrigerant flows into the expansion valve in a stable state, the refrigerant passing through the expansion valve can be appropriately controlled.

[0005] However, since proper shutoff is required during both cooling and heating operations, and the refrigerant shutoff device is located on the refrigerant circuit of the refrigeration cycle, it must be able to handle bidirectional refrigerant flow. If reverse pressure is applied to a shutoff valve that shuts off refrigerant flow in one direction, the valve body will vibrate regardless of the valve's open or closed state, potentially causing abnormal noise or valve failure. Furthermore, if the refrigerant piping on the indoor unit side of the shutoff valve becomes liquid-sealed when the refrigerant flow is shut off, there is a possibility that the refrigerant piping will rupture. To prevent this liquid-sealed state, it is necessary to add mechanisms such as a pressure regulating valve.

[0006] Therefore, there was a need for refrigerant shutoff devices and air conditioning systems that could properly shut off the refrigerant. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 7415017 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] This invention has been made in view of the problems of the prior art described above, and aims to provide a refrigerant shutoff device and an air conditioning device that appropriately shut off the refrigerant regardless of the location of the refrigerant leak. [Means for solving the problem]

[0009] In other words, according to the present invention, A refrigerant shutoff device that includes a refrigerant flow path that branches into a first refrigerant flow path and a second refrigerant flow path and merges therein, The first refrigerant flow path is It includes a first check valve that allows the refrigerant to pass in a first direction, and a first shut-off valve that blocks the flow of the refrigerant, The second refrigerant flow path is The system includes a mechanism that restricts the direction in which the refrigerant flows to a second direction different from the first direction, In the first refrigerant flow path, the first shut-off valve is positioned upstream of the first check valve in the first direction. A refrigerant shutoff device is provided. [Effects of the Invention]

[0010] According to the present invention, a refrigerant shutoff device and an air conditioning system can be provided that appropriately shut off the refrigerant regardless of the location of the refrigerant leak. [Brief explanation of the drawing]

[0011] [Figure 1] A diagram illustrating the refrigeration cycle in the air conditioning system of this embodiment. [Figure 2] This figure shows a first configuration example of the refrigerant shutoff device in this embodiment. [Figure 3] This figure shows a second example of the configuration of the refrigerant shutoff device in this embodiment. [Figure 4] This figure shows a third configuration example of the refrigerant shutoff device in this embodiment. [Figure 5] This figure illustrates an example of the arrangement of check valves that constitute the refrigerant shutoff device of this embodiment. [Modes for carrying out the invention]

[0012] The present invention will be described below with reference to embodiments, but the present invention is not limited to the embodiments described later. In the figures referenced below, the same reference numerals will be used for common elements, and their descriptions will be omitted as appropriate.

[0013] Figure 1 is a diagram illustrating the refrigeration cycle in the air conditioning system 10 of this embodiment. As shown in Figure 1, the refrigeration cycle in the air conditioning system 10 consists of an indoor unit 20 and an outdoor unit 30, which are connected via refrigerant piping 40. The indoor unit 20 is installed in the indoor space where air conditioning is performed, and the outdoor unit 30 is installed outside the said indoor space.

[0014] The indoor unit 20 is composed of an indoor heat exchanger 21 and an indoor fan 22. The outdoor unit 30 is composed of a compressor 31, a four-way valve 32, an outdoor heat exchanger 33, an expansion valve 34, and an outdoor fan 35. Here, the arrows in Fig. 1 indicate the direction in which the refrigerant flows during the cooling operation. In the following description of the refrigeration cycle, unless otherwise specified, for the sake of convenience, the operation during the cooling operation will be described as an example. During the heating operation, the direction in which the refrigerant flows is reversed from the direction of the arrow in Fig. 1.

[0015] The indoor unit 20 exchanges heat between the air in the indoor space and the refrigerant flowing through the indoor heat exchanger 21 by means of the indoor fan 22, and discharges the air back into the room again, thereby performing air conditioning in the indoor space. During the cooling operation, the indoor heat exchanger 21 operates as an evaporator, and exchanges heat between the low-temperature and low-pressure liquid refrigerant and the air blown from the indoor fan 22. The indoor unit 20 can lower the temperature of the indoor space by discharging the heat-exchanged air. The refrigerant flowing out of the indoor heat exchanger 21 is a low-temperature and low-pressure gas refrigerant, and flows to the outdoor unit 30 via the refrigerant pipe 40.

[0016] Next, the outdoor unit 30 will be described. The compressor 31 compresses the low-temperature and low-pressure gas refrigerant flowing in from the outdoor unit side by driving a motor, and discharges it as a high-temperature and high-pressure gas refrigerant. The gas refrigerant discharged from the compressor 31 flows into the outdoor heat exchanger 33 through the four-way valve 32. The outdoor heat exchanger 33 exchanges heat between the refrigerant flowing through it and the outside air sent in from the outdoor fan 35. During the cooling operation, the outdoor heat exchanger 33 operates as a condenser, and discharges the refrigerant as a high-temperature liquid through heat exchange. The outdoor heat exchanger 33 operates as an evaporator during the heating operation.

[0017] The refrigerant discharged from the outdoor heat exchanger 33 is expanded in volume by the expansion valve 34, and the temperature decreases due to decompression. Thereafter, the refrigerant flows to the indoor unit 20 and performs a cooling operation to lower the temperature of the indoor space as described above.

[0018] The four-way valve 32 is a valve that switches the refrigerant flow path according to the operating mode of the air conditioner 10. That is, during cooling operation, the connection is as shown by the solid line in FIG. 1, and during heating operation, the connection is as shown by the broken line. By doing so, either the indoor heat exchanger 21 or the outdoor heat exchanger 33 can operate as a condenser and the other as an evaporator, and appropriate air conditioning operation can be performed.

[0019] Note that the air conditioner 10 shown in FIG. 1 has a configuration in which one outdoor unit 30 is provided for one indoor unit 20, such as a so-called household air conditioner (also referred to as a room air conditioner), but the embodiment is not particularly limited. Therefore, the air conditioner 10 can have a configuration in which one or more outdoor units 30 are provided for a plurality of indoor units 20, such as a so-called commercial air conditioner (also referred to as a building multi-air conditioner, VRF (Variable Refrigerant Flow), etc.).

[0020] Also, as shown in FIG. 1, the air conditioner 10 of the present embodiment can be configured to include a refrigerant cutoff device 50 and a refrigerant leak detection sensor 60 in the refrigerant pipe 40 that connects the indoor unit 20 and the outdoor unit 30. The refrigerant cutoff device 50 of the present embodiment can operate to cutoff the refrigerant flow when the refrigerant leak detection sensor 60 detects a refrigerant leak. Note that the refrigerant cutoff device 50 and the refrigerant leak detection sensor 60 included in the air conditioner 10 of the present embodiment do not necessarily have to be two as shown in FIG. 1, and can be any number. Also, the position where they are arranged does not have to be the refrigerant pipe 40 that connects the indoor unit 20 and the outdoor unit 30 as shown in FIG. 1, and for example, they may be arranged inside the indoor unit 20 or inside the outdoor unit 30.

[0021] So far, the air conditioner 10 of the present embodiment has been described. Hereinafter, an example of the specific configuration of the refrigerant cutoff device 50 of the present embodiment will be described with reference to FIGS. 2 to 4. In the description of FIGS. 2 to 4 below, the description of the common configurations with the same reference numerals will be omitted as appropriate.

[0022] First, let's describe the first configuration example. Figure 2 is a diagram showing the first configuration example of the refrigerant shut-off device 50 in this embodiment. As shown in Figure 2, the refrigerant shut-off device 50 in this embodiment can be installed in the middle of the refrigerant piping 40 that connects the outdoor unit 30 and the indoor unit 20. As shown in Figure 2, the refrigerant shut-off device 50 is connected to the refrigerant piping 40 on the outdoor unit 30 side, branches (or merges) the refrigerant flow path into two, merges (or branches) again, and is connected to the refrigerant piping 40 once more. In other words, the refrigerant shut-off device 50 in this embodiment is configured to include a first refrigerant flow path 51 and a second refrigerant flow path 52.

[0023] The first refrigerant flow path 51 includes a shut-off valve 511 and a check valve 512. The first refrigerant flow path 51 is configured so that refrigerant flows in the direction of arrow A in Figure 2, that is, from the outdoor unit 30 to the indoor unit 20, and no refrigerant flows from the indoor unit 20 to the outdoor unit 30. In this embodiment, the shut-off valve 511 is positioned upstream of the check valve 512 in the direction in which the refrigerant flows in the first refrigerant flow path 51.

[0024] The shut-off valve 511 is a valve that shuts off the flow of refrigerant in the piping. The shut-off valve 511 in this embodiment may have a directionality in the direction in which the refrigerant flows, or it may be configured so that the refrigerant passes only in the direction in which the refrigerant flows in the first refrigerant flow path 51.

[0025] The check valve 512 is a valve that allows refrigerant to pass in only one direction and not in the reverse direction. The check valve 512 in this embodiment can allow refrigerant to pass only in the direction in which the refrigerant flows in the first refrigerant flow path 51 (the direction of arrow A; referred to as the first direction), and does not allow refrigerant flowing in the opposite direction to arrow A to pass through.

[0026] The second refrigerant flow path 52 is configured with a mechanism (hereinafter referred to as the refrigerant flow direction limiting mechanism 521) that restricts the flow of refrigerant to only one direction. In this embodiment, the second refrigerant flow path 52 is configured by the refrigerant flow direction limiting mechanism 521 so that the refrigerant flows in the direction of arrow B in Figure 2 (referred to as the second direction), that is, from the indoor unit 20 to the outdoor unit 30, and no refrigerant flows from the outdoor unit 30 to the indoor unit 20.

[0027] As shown in Figure 2, the refrigerant shut-off device 50 of this embodiment is configured to include a first refrigerant flow path 51 that allows refrigerant to pass only in a first direction, and a second refrigerant flow path 52 that allows refrigerant to pass only in a second direction opposite to the first direction. Therefore, when the air conditioning system 10 is operating normally, refrigerant can flow between the indoor unit 20 and the outdoor unit 30, whether in cooling or heating mode. In other words, the refrigerant shut-off device 50 of this embodiment can accommodate bidirectional refrigerant flow.

[0028] Furthermore, with the refrigerant shut-off device 50 configured as shown in Figure 2, for example, if a refrigerant leak occurs on the outdoor unit 30 side, even if the shut-off valve 511 shuts off the flow of refrigerant, the check valve 512 is positioned downstream of the shut-off valve 511 in the first direction, which allows the pressure from the indoor unit 20 side to the outdoor unit 30 side to be shut off. Therefore, vibration due to back pressure of the shut-off valve 511 can be prevented.

[0029] Furthermore, for example, if a refrigerant leak occurs on the indoor unit 20 side, the flow of refrigerant in the first refrigerant passage 51 from the outdoor unit 30 side to the indoor unit 20 side can be blocked by the shut-off valve 511. In this case, since the second refrigerant passage 52 only allows refrigerant to pass in the second direction, the flow of refrigerant from the outdoor unit 30 side to the indoor unit 20 side is also blocked in the second refrigerant passage 52. Therefore, the refrigerant shut-off device 50 of this embodiment blocks the flow of refrigerant from the outdoor unit 30 side to the indoor unit 20 side. And, since the second refrigerant passage 52 only allows refrigerant to pass in the second direction, even if the flow of refrigerant is blocked by the refrigerant shut-off device 50, it is possible to prevent the refrigerant piping 40 on the indoor unit 20 side from becoming liquid-sealed.

[0030] Next, a second configuration example will be described. Figure 3 is a diagram showing a second configuration example of the refrigerant shutoff device 50 in this embodiment. The second configuration example shown in Figure 3 is a concrete representation of the configuration of the refrigerant flow direction limiting mechanism 521. That is, the second configuration example replaces the refrigerant flow direction limiting mechanism 521 of the first configuration example with a check valve 522. Since the check valve 522 can also restrict the direction of refrigerant flow to one direction, the second refrigerant flow path 52 in the second configuration example is configured so that refrigerant flows from the indoor unit 20 to the outdoor unit 30, and no refrigerant flows from the outdoor unit 30 to the indoor unit 20.

[0031] Therefore, the refrigerant shut-off device 50 of the second configuration example can also prevent vibration due to back pressure of the shut-off valve 511 and prevent a liquid-sealed state when the shut-off valve 511 shuts off the refrigerant.

[0032] Next, a third configuration example will be described. Figure 4 shows a third configuration example of the refrigerant shut-off device 50 in this embodiment. The third configuration example shown in Figure 4 is a configuration in which a shut-off valve 523 is added to the second refrigerant flow path 52 in the second configuration example. Here, the shut-off valve 523 can be placed upstream of the check valve 522 in the second direction of the second refrigerant flow path 52. In other words, the first refrigerant flow path 51 and the second refrigerant flow path 52 in the third configuration example have the same configuration, differing only in the direction in which the refrigerant passes through.

[0033] Therefore, the refrigerant shut-off device 50 in the third configuration example, like the first and second configuration examples, can prevent vibration due to back pressure of the shut-off valve 511 and prevent a liquid-sealed state when the shut-off valve 511 shuts off. In addition, in the third configuration example, since the first refrigerant flow path 51 and the second refrigerant flow path 52 have the same configuration, they can be installed on the refrigerant piping 40 regardless of the installation direction (i.e., they can be installed without worrying about whether they are on the indoor unit 20 side or the outdoor unit 30 side), which reduces the effort required for the worker performing the installation.

[0034] Furthermore, in the refrigerant shut-off device 50 shown in Figures 2 to 4, the shut-off valves 511 and 523 can be solenoid valves configured to close when the device is not energized, from a fail-safe perspective. By using solenoid valves that close when the device is not energized, the refrigerant shut-off device 50 can be activated in the event of a power loss, thereby safely shutting off the flow of refrigerant.

[0035] Next, the arrangement of the check valves 512 and 522 of the refrigerant shut-off device 50 shown in Figure 3 will be explained with reference to Figure 5. Figure 5 is a diagram illustrating an example of the arrangement of the check valves 512 and 522 that constitute the refrigerant shut-off device 50 of this embodiment. In Figure 5, the areas indicated by the dashed rectangles are the check valves 512 and 522. The arrows in Figure 5 indicate the direction in which each check valve 512 and 522 can allow the refrigerant to pass.

[0036] As shown in Figure 5, in the refrigerant shut-off device 50 of this embodiment, the check valves 512 and 522 can be arranged vertically with respect to the direction in which the refrigerant passes. Generally, check valves are configured to restrict the direction in which fluid passes by closing through the force of a spring, the weight of the valve body, or the flow of fluid. In this embodiment, even with a check valve that does not use a spring, as shown in Figure 5, by arranging the check valves 512 and 522 so that the direction in which the refrigerant passes is from bottom to top, the valves can be easily closed by the weight of the valve bodies of the check valves 512 and 522. Therefore, as in the third configuration example shown in Figure 4, it is possible to have a configuration that does not depend on the direction in which the refrigerant is installed, even without providing a shut-off valve 523 in the second refrigerant passage 52.

[0037] According to the refrigerant shut-off device 50 of the embodiment described so far, if a refrigerant leak occurs on the outdoor unit 30 side, vibration due to back pressure of the shut-off valve 511 when the shut-off valve is shut off can be prevented. Furthermore, if a refrigerant leak occurs on the indoor unit 20 side, a liquid-sealed state can be prevented without the need to provide a pressure regulating valve or the like.

[0038] According to the embodiments of the present invention described above, it is possible to provide a refrigerant shutoff device and an air conditioning system that appropriately shut off the refrigerant regardless of the location of the refrigerant leak.

[0039] Although the present invention has been described above with reference to embodiments, the present invention is not limited to the embodiments described above. It is included within the scope of the present invention as long as it achieves the effects and advantages of the present invention within the range of embodiments that a person skilled in the art could conceive. [Explanation of Symbols]

[0040] 10…Air conditioning system, 20...Indoor unit, 21...Indoor heat exchanger, 22... Indoor fan, 30...Outdoor unit, 31... Compressor, 32... Four-way valve, 33...Outdoor heat exchanger, 34...Expansion valve, 35... Outdoor fan, 40... Refrigerant piping, 50... Refrigerant shutoff device, 51...First refrigerant flow path, 52...Second refrigerant flow path, 511...Shut-off valve, 512... Check valve, 521... Refrigerant flow direction limiting mechanism, 522... Check valve, 523...Shut-off valve, 60... Refrigerant leak detection sensor

Claims

1. A refrigerant shutoff device that includes a refrigerant flow path that branches into a first refrigerant flow path and a second refrigerant flow path and merges therein, The first refrigerant flow path is It includes a first check valve that allows the refrigerant to pass in a first direction, and a first shut-off valve that blocks the flow of the refrigerant, The second refrigerant flow path is It includes a second check valve that restricts the direction in which the refrigerant flows to a second direction different from the first direction, and a second shut-off valve that blocks the flow of the refrigerant, In the first refrigerant flow path, the first shut-off valve is positioned upstream of the first check valve in the first direction. In the second refrigerant flow path, the second shut-off valve is positioned upstream of the second check valve in the second direction. The refrigerant shutoff device is provided in each of the two connecting pipes that connect the indoor unit of the air conditioning system to the outdoor unit equipped with an expansion valve. Refrigerant shutoff device.

2. The first check valve and the second check valve are arranged such that the direction through which the refrigerant passes is from bottom to top. The refrigerant shutoff device according to claim 1.

3. The first shut-off valve is a solenoid valve that closes when the power is not supplied. The refrigerant shutoff device according to claim 1.

4. A refrigerant shutoff device according to any one of claims 1 to 3, Air conditioning system.

5. The first direction of the first refrigerant flow path is the direction from the outdoor unit to the indoor unit. The air conditioning device according to claim 4.

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